How To Can & Freeze Sweet Corn

Sweet corn like most vegetables is a low acid food and is only safely and dependably processed via a pressure canner. If you understand the basic principles of pressure canning you should have no trouble canning it.

Sweet Corn

Gathering Fresh Sweet Corn

The are two different ways to can sweet corn: raw pack or hot pack. The raw pack method is presented here and is the method that I prefer. The raw pack method saves time and energy.

With the raw pack method fresh raw corn kernels are packed into a Mason jar and then boiling water is poured into the jar.The jar is then sealed and processed in a pressure canner.The hot pack method is basically the same as the raw pack except the corn is pre-cooked or blanched before it is packed hot into a canning jar. The advantage of hot pack is that more corn can be put into a jar and the corn doesn’t tend to loose liquid in the jar during processing.
Gather and assemble the jars, lids, bands, jar lifter, funnel and the pressure canner before canning day. Nothing is worse than stopping in the middle of canning to go and hunt for something you forgot or replace equipment that doesn’t work properly.Check to make sure that everything is in good working order.

Visually examine all jars and rims for cracks, nicks or sharp edges. Examine the pressure canner and gasket carefully. Wash the jars and bands in hot soapy water and rinse well. Dry the bands and set aside. Keep the jars hot. An automatic dishwasher is perfect for this. But a sink full of hot water works just as well, as does pouring very hot water into upright jars as they stand in a sink or in a shallow pan.

Place the rack in the pressure canner and add the recommended amount of water according to your canner’s manufacturer.

Add Water To Canner

Add The Recommended Amount Of Water Into The Canner

Begin to heat the canner and heat a kettle of full of water while you are working. The water in the kettle will be poured into the jars to cover the corn. Simmer lids for 3 -5 minutes and keep hot until ready to use. Don’t boil them.
Try and time the simmering of the lids, hot water in the kettle and canner to coincide with when you will be ready to pack the jars.
Collect fresh picked sweet corn. Be careful not to try to do more than one canner load at a time. Corn is very perishable and will sour if left out for too long after being cut off the cob. Husk the corn, remove the silk and rinse well with cold water.

Sweet Corn

Sweet Corn Husked And Ready For Processing

While working quickly and without delay, cut the corn kernels from the cob and place into a bowl. Do not scrape the cobs.

Cutting Corn

A Nail Driven In At a Slight Angle Into a Wooden Cutting Board Holds the Corn in Place.

By now the water in the canner should be hot, the lids should be simmered and the kettle of water should be simmering too.
If you chose to add salt to your corn the standard measure is:
1 teaspoon for quarts
1/2 teaspoon for pints.
I use less than half those amounts for my corn. Fill a hot jar with corn taking care not to pack it in too tight or press it down leaving a 1″ head space. Pour boiling water into the jar and over the corn to 1/2″ of the top.

Pouring Water Over Corn

Pour Boiling Water Over Packed Sweet Corn

Slide a non-metallic object down the sides of the jar to release any trapped air bubbles. Carefully wipe the rim and sides of the jar with a clean wet cloth.

Wipe Jar Rim

Carefully Wipe The Rim Of The Canning Jar

Apply a lid and band.

Apply Lid

Apply A New Fresh Lid

Place the jar into the canner so it will remain hot while you work on filling the other jars.

Filling The Canner

Filling A Pressure Canner With Pint Jars Of Sweet Corn

Keep the water in the canner just at a simmer while you are working. When all the jars are filled put the lid on the canner and close it.
Heat the canner with the pressure control weight off and heat it until a steady stream of steam comes out of the vent. Allow the steam to vent from the canner for about 5 -10 minutes or according to your canner manufacturer’s directions. It is important to drive all of the air out of the canner especially if you are using a dial gauge. Air pressure and steam pressure together may give a faulty reading on a dial gauge.

Venting Canner

Canner Venting Before The Pressure Regulator Weight Is Put On

Once the canner has been properly vented, apply the control weight or close the petcock valve.Processing time is counted from the time the weight first begins to juggle or when 10 pounds of pressure is reached on the dial. A jiggle of 1 to 4 times a minute is about right. With a dial gauge the aim is to keep the heat steady so that the pressure remains stable. Some pressure canners have both a dial gauge and a regulator control weight.
Adjust the heat on the stove if necessary to keep and even and correct pressure throughout the entire processing time. It may take some trial and error to determine the heat setting on your stove to keep the pressure steady. If at any time pressure goes below the recommended amount, bring the canner back up to the correct pressure and begin the timing from the beginning .
Processing time for corn is:
55 minutes for Pints
1 hour and 25 minutes for Quarts
at 10 pounds of pressure.
Don’t forget to make adjustments in the processing time or pressure if you are above 1000 feet sea level.

The Amount Of Pressure Required To Reach 240° F

Sea Level-2,000 ft. 11 lb.
2,001-4,000 ft. 12 lb.
4,001-6,000 ft. 13 lb.
6,001-8,000 ft. 14 lb.
8,001-10,000 ft. 15 lb.

When the processing time is complete, you can either turn off the heat under the canner and allow the canner to stay on the burner to cool or you can carefully remove the canner from the heat. Allow the canner to cool naturally. Do not try to hasten the cooling process by using cold water or a fan. Only after canner pressure has returned to normal is it safe to open the lid .
For a control weight canner the pressure will have returned to normal when the vent stops hissing. If the control weight hisses at all when you touch it too much pressure is still inside the canner. Leave it alone and give it more time to cool.For a dial gauge canner when the gauge reads “0″ it is safe to open the canner.
Take care and use caution while opening the canner lid. All surfaces of the canner will be extremely hot. Always open the canner with the lid facing away from you and allow the hot water to run off inside the pot.

Remove Canner Lid Facing Away From You

Remove The Canner Lid Facing Away From You

Remove the jars from the canner and place the jars on a towel, board or thick layer of newspaper well out of the way of drafts.

Allow the jars to cool undisturbed for 8 – 12 hours. When the jars are completely cooled check the seal. Remove the screw band before checking the seal.

Corn Cooling

Sweet Corn Cooling After Processing

The seal is checked by gently lifting the jar by the lid and pushing down into the center of the lid. The lid should be slightly concave and have no spring to it.

Testing The Seal

Testing A Jar Seal

  • If the lid bounces up and down the jar has not seal and the corn should be frozen, reprocessed or eaten promptly.
    Jars should be wiped clean and stored in a cool dark place.
    ** A couple of hints about working with sweet corn**
    If at all possible cut sweet corn off the cob outdoors. Sweet corn is messy and sticky squirts everywhere when you cut if off the cob. Be sure to have plenty of wet cloths while you work to wipe your hands.You’ll probably have to clean off your knife a couple of times.
    Don’t work near a window or wall if you can help it. If you do, you’ll be cleaning windows and washing walls when you’re done. Don’t say I didn’t warn you.
    Sometimes liquid is lost in the canning jar. Don’t be concerned. As long as the seal is good the food will not spoil.
    Freezing corn is much simpler than canning corn and results in a product that is much fresher tasting.
    When I have leftover corn from canning that is not enough to make another full canner load I always freeze it. Corn for freezing is prepared exactly the same way as for canning; cut from the cob and handled in small amounts.There are several different ways to freeze corn.
    Here’s what works for me:
    Place the corn in a saucepan and add a small amount of water to it – just enough to barely cover the corn.Heat the corn over a medium heat for about 5 minutes. You want the corn to simmer just a bit and to partially cook. The corn will probably thicken a little and that’s okay.

    Blanching Corn

    Blanching Sweet Corn Before Freezing

    After about 5 minutes drain the corn into a sink and add ice to the corn after it has drained.After the corn has cooled you may have to pick out some ice if it hasn’t already melted.

    Cooling Sweet Corn

    Cooling Down Blanched Sweet Corn Quickly With Ice

    Pack the cooled corn into rigid containers, into freezer bags or into vacuumed sealed bags. Corn will last in the freezer for 12 -16 months depending upon freezer conditions.